Method of regulating and controlling the production of steam.



K E. THOMSON. v

METHOD OF REGULATING AND CONTROLLING THE PRODUCTION OF STEAM.

APPLIGATiON FILED NOT/.17, 1902.

Patented Jan. 30, 1912.

Atty

m M M WITNESSES:

UNITED STATES PATENT OFFICE.

ELIHU THOMSON, 013 SWAMPSCOTT, MASSACHUSETTS, ASSIGN OR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

METHOD OF REGULATING AND CONTROLLING THE PRODUCTION OF STEAM.

Specification of Letters Patent.

Patented Jan. 30, 1912.

Original application filed August 2, 1897, Serial No. 646,752. Divided and this application filed November 17, 1902. Serial No. 131,642.

'n all whom it may concern:

Be it known that I, ELIHU THo soN, a citizen of the United States, residing at Swampscott, in the county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Methods of Regulating and Controlling the Production of Steam, of which the following is a specification.

The present application is a division of my pending application Serial No. 646,752, filed August 2, 1897, which division made under the requirements of Rules 41 and 42 of'the United States Patent Oflice.

My present invention relates to the method of controlling or limiting the temperature to be attained by a steam-generating device or boiler, and also for limiting the pressure which can at any time be produced therein by vaporization of a fluid pumped into'the vaporizing space. 1 p

The invention is particularly applicable to a vaporizer or boiler made of a massive piece of metal in accordance with other cases filed by me, or such a structure as consists of a metallic body having passages through which the vapors of a fluid are to be sent. The metallic body in this case is assumed to be sufiiciently massive to acquire a sensibly uniform temperature by heat conduction, or-at least not to differ very greatly in temperature at different portions.

The invention has for its object to provide an improved method of regulating and controlling the production of steam wherein the temperature attained at some one part or parts of the boiler structure controls any increase beyond a certain limit in such temperature and at the same time controls the pressure which may be developed in the vapor stream by regulating the water or fluid supply.

Figure 1 represents an. elevation, partly in section, of a structure embodying my in vention. Fig. 2 is a plan of the parts shown in Fig. 1. Figs. 3 and 4 are enlarged details. Fig. 5 is a modification adapting the invention to a particular use.

In Fig. 1, V represents a massive vapor-- i'zer whose exterior surfaces are covered with projections for absorbing heat and jet J through a pipe P from=any sultable reservoir, under sufiicient pressure to cause it to flow. R is a valve which can be opened and shut by a motion of the valve rod r, to regulate the flow of vapor or oil to the burner J. Q, is 'a portion of the mass of the boiler V, extended to contain the temperature regulating arrangement, which may be constructed in various ways. One of these ways is typified in Fig. 3; here the exten sion Q of the boiler mass (which may, of course, be a metallic piece attached to the mass having thorough heat-conducting connection therewith), contains .a compound bar B of two metal strips 1) and I) having diflierent coeflicients of expansion by heat, fixed at one end, and adjusted by a proper screw Z so that it will press upon the valve rod 1', Fig. 1, and allow full flow of the fuel to heat the vaporizer. On the increase of temperature of the vaporizer V and the boss Q, in sympathy therewith the compound bar B bends so as to relieve the rod 1' and close the valve R (Fig.1); gradually, upon the attainment of a certain temperature, the valve closes, either nearly or completely, as may be desired. In this arrange-' ment, if the valve R be opened by the spring and closed by the flexure of the compound bar, the temperature of the met-a1 mass of the vaporizer V will be limited or controlled irrespectively-of its duty or vapor output. The compound bar B might of course be replaced by an expansible fluid contained in a flattened tube, as in'the Bourdon pressure gage, or by any suitable heat-responsive devices capable of controlling the valve R and the fuel supply, the chief object of the arrangement being to check the fire or the heating agent-inits action in heating the vaporizer V in accordance with the increased temperature of said vaporizer, ir-

respective of the pressure of the vapor developed or the amount of vapor developed in the heater.

With the devices so far described I combine the automatic control of the pressure of the liquid to be vaporized, and thereby I am enabled to control not only the temperature of the vapor which leaves the boiler, but also and simultaneously the pressure of the vapor. .The vaporizer then cannot produce either an excessive pressure of vapor, nor can it produce it at an excessive temperature. It is in fact preferred to locate the boss Q at or near the outlet 0 so as to more perfectly accomplish the result just stated. The object of my vaporizer is to supply steam to engines under regulated pressure and at such a temperature as will not injure the moving parts. At the same time the object is to utilize when desired massive vaporizers with practically no water therein, or with so little water that no similarity exists between it and an ordinary steam boiler filled with boiling water. For securing vapor at a pressure limited in amount therefore ll employ a feed pump D (Fig. I) worked by a crank and plunger within a cylinder E in the ordinary way. This teed pump has the usual system of valves between its outlet pipe I and its inlet or suction pipe S (see Fig. 4), opening from the suction pipe inward to the pump cylinder and from the pump cylinder outward to the pipe I, as usual. An air chamber A, with air under pressure, is preferably located between the pump and the vaporizer. The suction ipe S communicates with a supply of liqui to be vaporized, which may be water, oil or other liquid. The pump is worked at such a rate as will give an excessot liquid over any possible demand or up to that amount which the vaporizer V under full work is capable of converting into vapor. Should however the outlet pipe 0 be closed '(as by a valve between the vaporizer and an engine using the vapor) the pump D need not stop, because a valve is provided at W, held by a spring and allowing under a certainexcess of pressure the liquid taken into the pump cylinder E through the valve ,S to pass back into the suction space or pipe S, instead of passing the outlet valve T into the pipe I. Upon the valve W bears a spring. F which may be adjusted by any suitable means on the stem of the valve W, so as to cause it to open under a certain pressure, which is to be the maximum pressure to be generated in the vaporizer. The slipvalve W being located in the suction space gives freedom from the leakage which might otherwise exist if it were located on the pipe I or elsewhere where the pressure is high.

oraeea the pressure-regulating part and the temperature-regulating part work togehter, as

when the vaporizer V is used to vaporize oil, which is used to supply the 'jet J, and which may-also be vaporized for working an engine, the oil being condensed after passing the engine and returned to a proper reservoir from which the suction pipe S takes it. In this case (see Fig. 5) S would be a suction pipe for oil from a suitable tank or reservoir. The valve W would be set, as before, to 'limit the pressure which the pump would exert in forcing said oil forward. The chamber A would exist as an equalizer and steadier of the pressure, as well as a reservoir for liquid under pressure. The valve R would be controlled, as in Fig. l, by the temperature of the vaporizer, and thereby the flow of compressed oil to the jet J would be governed. A side pipe I may take a portion of the pumped oil, under pressure, and carry it through the vaporizer, as in Fig. 1, and the vaporized oil would pass to the outlet pipe 0 where it may be used for working a vapor engine and \afterward suitably condensed and returned to the reservoir from which the pipe S takes it.

Uther modifications of my invention can readily be made, its essential features consisting in so combining the regulation for temperature of the vaporizer and the pressure of the vapor generated as to secure a flow of vapor of limited temperature and pressure, but varying in amount according to the demand, while the fuel which produces the vaporization is also varied in amount or rate of combustion automatically according to the demand for heat. To state the matter in a difl'erent way, means are provided t'or supplying water to the boiler and fuel to the combustion chamber or burner in such quantities as will furnish the desired amount of superheated steam or vapor under varying conditions of load up to the capacity of the system. As the demand for superheated steam or vapor varies, the thermostat and pressure regulator automatically vary the amounts of water and fuel which are respectively supplied to the boiler and burner, and this in a definite quantitative relation to said variation in demand and in substantially the same degree. lln this manner the temperature and pressure of the vapor are constantly maintained atv the proper points and under economical and satisfactory conditions.

The generator being of the flasher type. the water as it enters is gradually heated until it flashes into steam, and from this point to the end'is gradually superheated. This means that only a small amount of water is atthe temperature of vaporization As the demand on the generator for vapor changes the point of vaporization changes slightly. In one case it may be midway between the ends of the tube, and in another before or after the midway position.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is,

1. The'method' of generating vapor which consists in supplying liquid to a generator and fuel to a burner, regulating the supply of liquid to the generator in accordance with the pressure of the vapor generated,

and regulating the supply of fuel to the burner in accordance with the temperature of said vapor.

2. The method of generating vapor which consists in supplying liquid to a generator and fuel to a burner, regulating the supply of liquid to the generator in accordance with changes in pressure of the vapor generated, by-passing the excess liquid from the generator, and regulating the supply of fuel to the burner in accordance with changes in temperature of the vapor.

In Witness whereof I have hereunto set my hand this 14th day of November, 1902.

ELIHU THOMSON.

Witnesses:

DUGALD MoK. MoKILLoP, HENRY O. WESTENDARP. 

